6 freelancers are bidding on average $157 for this job

libmodbus is being supported in meta-oe, so all needs is simply adding it, about libxml, another 2 options can be libxml++, libtinyxml, both of them are c++ wrappers of libxml2.
Relevant Skills and Experience
I am a yMore

So basically you wan an application, developed for/runs on Yocto machine. It is interesting and I can do it. I will setup a yocto dev. platform to do the task.
Relevant Skills and Experience
I have worked on on Yocto:More

I have 4 years of experience of yocto based embedded linux development and have previously compiled libmodbus for different platforms. You can see my github repo [url removed, login to view] for my previous work. I can eaMore